Article

Carbon Dioxide Exchange Between Atmosphere and Ocean and the Question of an Increase of Atmospheric CO2 During the Past Decades

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

From a comparison of C14/C12 and C13/C12 ratios in wood and in marine material and from a slight decrease of the C14 concentration in terrestrial plants over the past 50 years it can be concluded that the average lifetime of a CO2 molecule in the atmosphere before it is dissolved into the sea is of the order of 10 years. This means that most of the CO2 released by artificial fuel combustion since the beginning of the industrial revolution must have been absorbed by the oceans. The increase of atmospheric CO2 from this cause is at present small but may become significant during future decades if industrial fuel combustion continues to rise exponentially.Present data on the total amount of CO2 in the atmosphere, on the rates and mechanisms of exchange, and on possible fluctuations in terrestrial and marine organic carbon, are inadequate for accurate measurement of future changes in atmospheric CO2. An opportunity exists during the International Geophysical Year to obtain much of the necessary information.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Because of linearity -integration and derivative commute - (15) does not change in terms of the mean variables, which suggests to keep the simpler notations of (15), thus posing x=x and u=ū . A similar equation but referred to the ocean reservoir was written by Revelle in [39]. ...
... Literature estimates are rather sparse. Revelle [39] estimates for the ocean sink 10 years. Archer [23] computes 100 years. ...
... The atmospheric equation is similar to (39), but includes all the anthropogenic emissions as follows 29 The set of the equations (38), (39) and (40) may be referred to the as the carbon exchange equations of the biosphere. We can prove that ẋ 0 (t )= ∑ h=1 5ẋ h (t )=0 , in agreement with the conservation equation (36). ...
Preprint
Full-text available
The paper has been suggested by two observations: 1) the atmospheric CO2 growth rate is smaller than that ascribed to the emission of fossil fuels combustion, 2) the fossil fuel reserves are finite. The first observation has lead the way to a simple kinetic mode, based on the balance of 1) land/ocean CO2 absorption and 2) CO2 anthropogenic emission limited solely by depletion of the present day fossil-fuel reserves, in a business-as-usual scenario. The second observation has suggested to extrapolate past CO2 emissions by fossil fuel combustion in the future years up to 2200 CE, by constraining emissions to the physical limits of reserves availability. The Meixner curve (hyperbolic secant distribution) has been used to model the pathway of resource exploitation for the three main classes of fossil fuels, crude oil, natural gas and coal. The kinetic model, driven by the extrapolated emissions, has been employed to project the CO2 atmospheric concentration due to fossil fuel combustion close to the zero-reserve epoch. The result is just the output of simple models tuned on well-known experimental data. Error analysis of literature data provides the method robustness and the relevant uncertainty band. Contribution of other greenhouse gases like methane and nitrous oxide has been neglected, since their emissions cannot be projected with the paper methodology (they do not derive from fossil reserves). Notwithstanding this limitation, paper results clearly demonstrate that some of the IPCC projections of the CO2 concentration are largely overestimated if compared to the physical limits of fossil fuel exploitation.
... Here, we identify a mechanistic constraint for the global ocean Cant sink across 17 ESMs from CMIP6 (Table A. (Marshall and Speer, 2012;Talley, 2013;Buckley and Marshall, 2016;McCarthy et al., 2020). In addition, the Revelle factor accounts for biases in the biogeochemical buffer capacity of the ocean, i.e., the relative increase in ocean CT for a given relative increase in ocean pCO2 (Revelle and Suess, 1957). As the Revelle factor quantifies relative increases in ocean CT, the increase in surface ocean Cant depends on the Revelle factor and the natural surface ocean CT. ...
... The constraint must be relying on well understood mechanisms, that mechanism must be reliable, and the constraint must be validated in an independent model ensemble. Here, the well understood mechanisms are the fundamental ocean biogeochemical properties 290 such as the Revelle factor (Revelle and Suess, 1957), as well as the Southern Ocean and North Atlantic large-scale ocean circulation features that are known to be the determining factors for the ocean ventilation (Marshall and Speer, 2012;Talley, 2013;Buckley and Marshall, 2016). For the Southern Ocean, the verification was previously done by testing the robustness of the constraint to changes in the definition of the inter-frontal zone (Terhaar et al., 2021b). ...
... The years were centred around 2002 to make the Revelle factor comparable to the one estimated based on GLODAPv2, which is normalized to the year 435 2002 (Lauvset et al., 2016). As the Revelle factor describes the relative change in CT per relative change in pCO2 (Revelle and Suess, 1957), the absolute uptake of CT does not only depend on the Revelle factor but also on the natural CT in the surface ocean. To calculate the buffer capacity for each ESM, the Revelle factor was therefore adjusted in each grid cell by multiplying it by the ratio of observed CT and the simulated CT in each ESM separately. ...
Preprint
Full-text available
The ocean slows global warming by currently taking up around one quarter of all human-made CO2 emissions. However, estimates of the ocean anthropogenic carbon uptake vary across various observation-based and model-based approaches. Here, we show that the global ocean anthropogenic carbon sink simulated by Earth System Models can be constrained by two physical parameters, the present-day sea surface salinity in the subtropical-polar frontal zone in the Southern Ocean and the strength of the Atlantic Meridional Overturning Circulation, and one biogeochemical parameter, the Revelle factor of the global surface ocean. By exploiting this three-dimensional emergent constraint with observations, we provide a new model- and observation-based estimate of the past, present and future global ocean anthropogenic carbon sink and show that the ocean carbon sink is 9–11 % larger than previously estimated. Furthermore, the constraint reduces uncertainties of the past and present global ocean anthropogenic carbon sink by 42–59 % and the future sink by 32–62 % depending on the scenario, allowing for a better understanding of the global carbon cycle and better targeted climate and ocean policies. The here identified key parameters for the ocean carbon sink should be quantified when presenting simulated ocean anthropogenic carbon uptake as in the Global Carbon Budget and be used to adjust these simulated estimates if necessary. The larger ocean sink results in enhanced ocean acidification over the 21st century, which further threatens marine ecosystems by reducing the water volume that is projected to be undersaturated towards aragonite by around 3.7–7.4 million km3 more than originally projected.
... They can be used to test hypotheses on the roles of underpinning processes and to formulate predictions, e.g. on future CO 2 concentrations in the atmosphere for various emission scenarios. A number of carbon cycle models have been proposed, ranging from relatively simple box models (4) over box diffusion models with various degrees of complexity (2,(5)(6)(7) to computationally expensive models with three-dimensional grid structures for the atmosphere and the ocean (8) . Actually, also conceptually relatively simple models may provide useful insights as well as valuable predictions on the future behaviour of the carbon cycle (9) . ...
... The conversion factor = 4.347 m 2 Gt mol −1 is the product of carbon molar mass and ocean surface. Revelle factor ξ accounts for the ocean buffering capacity (4) . In this work, its dependence (10) on the dissolved inorganic carbon (DIC) was approximated, for a constant alkalinity of 2.35 mM and DIC ranging from 1.9 to 2.4 mM, as follows: ...
Article
Carbon cycle receives growing attention, in particular in connection with the climate change. Radiocarbon (14C) serves not only as the well-known basis of a dating technique but also as a tracer of the global carbon cycle, enabling one to assess the sizes of diverse compartments, fluxes between them and the related characteristic times. Mathematical modelling of the carbon cycle helps integrate the measurements, estimate the roles of underpinning processes and provide predictions, for instance on future CO2 concentrations in the atmosphere for various emission scenarios. We present a model based on a single-box atmosphere, ocean surface layer, one-dimensional diffusive ocean and two-box biota. We discuss its validation against measured data, predictions on future CO2 levels and interpretation of past events on the radiocarbon calibration curve.
... Revelle and Suess realized this mistake in 1957 (ref. 11). Thereafter, the perspective of the scientific community on the issue of human-induced climate change shifted rapidly 12,13 , especially after Keeling confirmed in 1960 that atmospheric CO 2 was increasing much more rapidly than implied by Arrhenius 14 . ...
Article
The ocean has absorbed 25 ± 2% of the total anthropogenic CO2 emissions from the early 1960s to the late 2010s, with rates more than tripling over this period and with a mean uptake of –2.7 ± 0.3 Pg C year–1 for the period 1990 through 2019. This growth of the ocean sink matches expectations based on the increase in atmospheric CO2, but research has shown that the sink is more variable than long assumed. In this Review, we discuss trends and variations in the ocean carbon sink. The sink stagnated during the 1990s with rates hovering around –2 Pg C year–1, but strengthened again after approximately 2000, taking up around –3 Pg C year–1 for 2010–2019. The most conspicuous changes in uptake occurred in the high latitudes, especially the Southern Ocean. These variations are caused by changes in weather and climate, but a volcanic eruption-induced reduction in the atmospheric CO2 growth rate and the associated global cooling contributed as well. Understanding the variability of the ocean carbon sink is crucial for policy making and projecting its future evolution, especially in the context of the UN Framework Convention on Climate Change stocktaking activities and the deployment of CO2 removal methods. This goal will require a global-level effort to sustain and expand the current observational networks and to better integrate these observations with models. Carbon uptake by the ocean has increased alongside rising atmospheric CO2 concentrations, but with substantial variability. This Review examines trends in ocean CO2 uptake and the internal and external factors driving its variability, finding an ocean uptake of –2.7 ± 0.3 Pg C year–1 for the period 1990 through 2019. The long-term trend in the ocean carbon sink since the early 1960s was primarily driven by the increasing uptake of anthropogenic CO2. Although the ocean is expected to have lost a few petagrams of natural CO2 to the atmosphere in response to ocean warming, this loss cannot be quantified conclusively with observations.The oceanic uptake of anthropogenic CO2 scaled proportionally with the increase in atmospheric CO2 between the early 1960s and late 2010s, as expected given the quasi-exponential growth of atmospheric CO2 during this period.The average ocean uptake rate of –2.7 ± 0.3 Pg C year–1 for the period 1990 through 2019 is commensurate with a sensitivity β of 1.4 ± 0.1 Pg C per ppm atmospheric CO2, suggesting a trend in the uptake of –0.4 ± 0.1 Pg C year–1 per decade.The annual mean ocean carbon sink varies by about ±20% around this trend, primarily caused by changes in the sources and sinks of natural CO2, with a lesser role for variations in atmospheric CO2 growth rates impacting the uptake of anthropogenic CO2.The net oceanic uptake rate of CO2 will likely decrease in the future owing to several converging trends: reduced emissions of CO2 leading to reduced atmospheric CO2 growth rates in response to climate policy; reduced storage capacity owing to continuing ocean acidification; and enhanced outgassing of natural CO2 owing to ocean warming and changes in ocean circulation and biology. The long-term trend in the ocean carbon sink since the early 1960s was primarily driven by the increasing uptake of anthropogenic CO2. Although the ocean is expected to have lost a few petagrams of natural CO2 to the atmosphere in response to ocean warming, this loss cannot be quantified conclusively with observations. The oceanic uptake of anthropogenic CO2 scaled proportionally with the increase in atmospheric CO2 between the early 1960s and late 2010s, as expected given the quasi-exponential growth of atmospheric CO2 during this period. The average ocean uptake rate of –2.7 ± 0.3 Pg C year–1 for the period 1990 through 2019 is commensurate with a sensitivity β of 1.4 ± 0.1 Pg C per ppm atmospheric CO2, suggesting a trend in the uptake of –0.4 ± 0.1 Pg C year–1 per decade. The annual mean ocean carbon sink varies by about ±20% around this trend, primarily caused by changes in the sources and sinks of natural CO2, with a lesser role for variations in atmospheric CO2 growth rates impacting the uptake of anthropogenic CO2. The net oceanic uptake rate of CO2 will likely decrease in the future owing to several converging trends: reduced emissions of CO2 leading to reduced atmospheric CO2 growth rates in response to climate policy; reduced storage capacity owing to continuing ocean acidification; and enhanced outgassing of natural CO2 owing to ocean warming and changes in ocean circulation and biology.
... Indeed, the figure is not far from the oceanic flux quoted above. Furthermore the turnover time figure compare very reasonably with older estimates by Revelle &Suess 1957 ~ 10yrs, andArnold &Anderson 1957 of 10 -20yrs, these being referred to (respectively) as "the average lifetime of a CO2, molecule in the atmosphere before it is dissolved into the sea" and "the mixing half-time between the atmosphere and ocean". It is extremely unlikely the above results would occur by chance given the excellent mean quality of fit for Δ 14 C and δ 13 C, and the reasonable values for six of the seven solution parameters, together with the reasonable explanation for the discrepancy in the other parameter, atmospheric outflow. ...
Preprint
Although total nett CO2 atmospheric flow can be estimated with reasonable accuracy, the contributing gross fluxes between the atmosphere and the earth's surface are poorly understood. This paper presents a method, driven by the objective of simplicity, by which the global outflow and inflow of CO2 between atmosphere and a globally equivalent "mixing reservoir" can be estimated, using the isotopes 14C and 13C as tracers. It has been asserted that the isotopic carbon in CO2 cannot be directly used as a tracer in flow studies because it is not subject to the Revelle factor. Evidence is provided showing that this view is mistaken. The model contains 7 key parameters which are used to create synthetic records of Δ14C and d13C spanning 200 years or more, including during the period of atmospheric weapons testing and its decay known as the "bomb pulse". By optimising the fit between these computed values and the historical records of d13C and Δ14C, all seven key parameters are determined. The effective "mixing reservoir" is thereby determined to have a size around six times that of the atmosphere, with global outflux rising from 39.7 GTC yr-1 in 1750 to 58.9 GTC/yr in 2020, this figure probably not including annually cycled carbon.
... After the isotopic analysis, we corrected the individual values of δ 13 C by decade, considering the Suess effect. This process describes the decline in the δ 13 C values of the atmosphere due to the input of anthropogenic CO 2 on Earth, mainly as a result of the increased burning of fossil fuels (Revelle and Suess, 1957). We used data from the literature to obtain values of δ 13 C atm per decade from 1900 to 1960, the timescale of our samples (Francey et al., 1999). ...
Article
Full-text available
Niche partitioning is a widespread ecological strategy within trophic guilds, ensuring the coexistence of sympatric species by reducing interspecific competition. Stable isotope analysis of carbon and nitrogen and isotopic niche metrics (width and overlap) are used as a proxy to investigate niche partitioning among species of a guild. In our study, we investigated if niche partitioning was an ecological mechanism contributing to the coexistence of granivorous birds from the same geographic region along time, employing an isotopic approach. We sampled and isotopically analyzed (δ¹³C and δ¹⁵N values) wing feathers from 58 specimens of granivorous birds collected between 1900 and 1966 in southeastern Brazil. We grouped birds according to the main habitat type used by them (forest: Cyanoloxia brissonii, Leptotila rufaxilla, and Leptotila verreauxi; and grassland: Columbina squammata and Sicalis flaveola). We used the Isotopic Richness (IRic) metric to measure the isotopic niche width and the Isotopic Similarity (ISim) and Isotopic Nestedness (INes) metrics to measure the niche overlap between groups and species. The results of low isotopic niche overlap suggest that common granivorous birds had a clear niche partitioning in southeastern Brazil in the late past, especially through foraging in distinct habitat types (forest and grassland; ISim = 0.1, INes = 0.2). Niche overlaps in almost all species-by-species comparisons were low (ISim ≤0.3, INes ≤0.4), except between C. brissonii and L. verreauxi (ISim = 0.6, INes = 1.0). These results suggest that these birds, belonging to the same trophic guild, coexisted through niche and resource partitioning. Despite being considered a plastic trophic guild, the isotopic niche partitioning among granivorous birds indicates that each of these species uses a set of specific resources and habitats. This raises an ecological concern about the homogenization of landscapes across the Neotropics, oversimplifying food resources and habitats to granivorous birds.
... With the end of the LIA, the rising temperature was welcomed with positive prospects, with some scholars writing about doubling carbon dioxide concentrations and its relationship to rising temperatures (Arrhenius, 1896). The discourse of how greenhouse gases can contribute to a warming Earth was deemed desirable until about the middle of the 20th century when researchers found that atmospheric carbon dioxide was not easily absorbed by oceans (Revelle & Suess, 1957), fuelling fears that the Earth was indeed warming beyond control. ...
... This buffer process was first quantified by Revelle and Suess (1957), who defined the Revelle factor as (Eq. 1): ...
Article
Full-text available
In a karstic area affected by acid mine drainage (AMD), hydrochemical conditions, such as temperature, salinity, alkalinity, DIC, dissolved oxygen, and nutrients, may affect the buffering capacity of carbonate systems in freshwater systems. The resulting pH fluctuation is larger than that of a marine system. Therefore, this study focuses on the buffering of a riverine carbonate system under the input of AMD and discusses the variations in a series of buffering factors, including the Revelle factor, γ DIC , γ Alk β DIC , β Alk , ω DIC , and ω Alk . The results revealed that the Revelle factor could reflect the buffering process effectively; in addition, the maximum value of the Revelle factor appeared at pH = 8.5. The data points for pH greater than this value indicated that the Huatan River had the ability to absorb atmospheric CO 2 in spring. Conversely, the data for pH less than this value reflected the buffering of H ⁺ during CO 2 degassing in summer and autumn. In winter, the data were around the maximum value, indicating the weakest buffering capacity. As a result, the dynamics of the carbonate system caused the most sensitive response to pH. In addition, the maximum Revelle factor value did not always indicate the carbonate system had reached equilibrium; the presence of strong CO 2 degassing was still a possibility. Under acidic conditions, as CO 2(aq) increased, the absolute values of γ DIC , β DIC , ω DIC , and γ Alk increased correspondingly, indicating the enhanced buffering capacity of H ⁺ during CO 2 degassing. Under the four Representative Concentration Pathways scenarios (RCPs) included in the IPCC’s fifth assessment report, the degassing rate of the Huatan River would decrease by 5%, 15%, 26%, or 48%, depending on the scenario. Even though the Huatan River revealed CO 2 degassing characteristics in winter and spring under current conditions, it will eventually become a sink for atmospheric CO 2 as atmospheric CO 2 concentration increases. In this light, the carbon sink effect in karst areas will become increasingly important.
... The other community was interested in the role of the ocean as a sink of anthropogenic carbon. Building on concepts established by Roger Revelle 6 , early ocean carbon cycle models did not include an explicit representation of plankton [7][8][9] . In the seminal work by Ernst Maier-Reimer 10,11 , models of carbon cycling and plankton dynamics were combined and integrated into global ocean circulation models. ...
Article
Ocean biogeochemical models describe the ocean’s circulation, physical properties, biogeochemical properties and their transformations using coupled differential equations. Numerically approximating these equations enables simulation of the dynamic evolution of the ocean state in realistic global or regional spatial domains, across time spans from years to centuries. This Primer explains the process of model construction and the main characteristics, advantages and drawbacks of different model types, from the simplest nutrient–phytoplankton–zooplankton–detritus model to the complex biogeochemical models used in Earth system modelling and climate prediction. Commonly used metrics for model-data comparison are described, alongside a discussion of how models can be informed by observations via parameter optimization or state estimation, the two main methods of data assimilation. Examples illustrate how these models are used for various practical applications, ranging from carbon accounting, ocean acidification, ocean deoxygenation and fisheries to observing system design. Access points are provided, enabling readers to engage in biogeochemical modelling through practical code examples and a comprehensive list of publicly available models and observational data sets. Recommendations are given for best practices in model archiving. Lastly, current limitations and anticipated future developments and challenges of the models are discussed. Ocean biogeochemical models use coupled differential equations to describe the transformation of the ocean’s circulation, physical and biogeochemical properties under different conditions. This Primer introduces the process of model construction and explains the characteristics of various model types, from simple to complex, alongside their advantages and disadvantages.
... In 1957, oceanographer Roger Revelle and chemist Revelle and Suess (1957) published what has been called the most famous sentence in the literature on global warming: "Human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future." The risk factor in this 'experiment' is known as positive radiative forcing, measured in units of watts per square meter, which is the difference between the amount of energy in sunlight striking the earth's surface less the amount that is re-radiated back into space. ...
Article
Full-text available
Risk management decisions in public health require consideration of a number of complex, often conflicting factors. The aim of this review was to propose a set of 10 fundamental principles to guide risk decision-making. Although each of these principles is sound in its own right, the guidance provided by different principles might lead the decision-maker in different directions. For example, where the precautionary principle advocates for preemptive risk management action under situations of scientific uncertainty and potentially catastrophic consequences, the principle of risk-based decision-making encourages decision-makers to focus on established and modifiable risks, where a return on the investment in risk management is all but guaranteed in the near term. To evaluate the applicability of the 10 principles in practice, one needs to consider 10 diverse risk issues of broad concern and explore which of these principles are most appropriate in different contexts. The 10 principles presented here afford substantive insight into the process of risk management decision-making, although decision-makers will ultimately need to exercise judgment in reaching appropriate risk decisions, accounting for all of the scientific and extra-scientific factors relevant to the risk decision at hand.
... The reason that pCO 2 and [H + ] are more sensitive to smaller, subsurface C anth changes in the open and coastal North Pacific is related to the background chemistry of these waters. The ocean's ability to buffer the chemical changes imposed by C anth addition is often quantified using the Revelle sensitivity Factor (Broecker et al., 1979;Egleston et al., 2010;Fassbender et al., 2017;Middelburg et al., 2020;Revelle & Suess, 1957;Sabine et al., 2004). RF is defined as the ratio between a fractional change in pCO 2 and a fractional change in DIC for a given carbonate system perturbation, assuming constant alkalinity: ...
Article
Full-text available
Plain Language Summary The ocean mitigates the extent of global warming by absorbing a portion of the carbon dioxide gas (CO2) released into the atmosphere by human activities. However, this comes at a cost to ocean health because the uptake of this anthropogenic CO2 causes changes in ocean chemistry, called ocean acidification (OA), that can be detrimental to marine ecosystems. This study explores how OA metrics have changed in the upper waters of the open North Pacific Ocean and coastal California Current Large Marine Ecosystem (CCLME). We focus on the CCLME due to its global importance and economically important fisheries. We find that different OA metrics exhibit different patterns of change with depth in the water column due to the natural, background ocean chemistry. One such metric shows that there is now more subsurface water containing CO2 levels elevated enough to threaten the health of marine organisms than there was before the anthropogenic CO2 addition. Our finding of expanded volumes of water with high‐CO2 levels near the coast is important to consider as a source of stress for marine organisms living both on the seafloor and in the water column.
... Ice remembers and records a dazzling array of past geological transformations and more recent human interventions. Trapped in ice bubbles, sediments and chemicals offer up the tantalizing prospect of reconstructing past climate and 'cryo-histories', including the composition of air thousands of years ago (Revelle and Suess, 1957;Sörlin, 2015). ...
Book
Ice humanities is a pioneering collection of essays that tackles the existential crisis posed by the planet's diminishing ice reserves. By the end of this century, we will likely be facing a world where sea ice no longer reliably forms in large areas of the Arctic Ocean, where glaciers have not just retreated but disappeared, where ice sheets collapse, and where permafrost is far from permanent. The ramifications of such change are not simply geophysical and biochemical. They are societal and cultural, and they are about value and loss. Where does this change leave our inherited ideas, knowledge and experiences of ice, snow, frost and frozen ground? How will human, animal and plant communities superbly adapted to cold and high places cope with less ice, or even none at all? The ecological services provided by ice are breath-taking, providing mobility, water and food security for hundreds of millions of people around the world, often Indigenous and vulnerable communities. The stakes could not be higher. Drawing on sources ranging from oral testimony to technical scientific expertise, this path-breaking collection sets out a highly compelling claim for the emerging field of ice humanities, convincingly demonstrating that the centrality of ice in human and non-human life is now impossible to ignore.
... I primi a richiamare l'attenzione sul pericolo rappresentato dall'aumento delle emissioni di CO 2 per gli equilibri climatici del pianeta sono stati il geologo americano Roger Revelle e il chimico austriaco Hans Suess, con un articolo pubblicato su Tellus nel 1957 che a oggi ha collezionato 1275 citazioni (Revelle & Suess, 1957). Tuttavia, sono passati molti anni prima che il problema divenisse di centrale importanza per la comunità scientifica internazionale. ...
Article
Full-text available
La teoria del riscaldamento globale gode oggi di un considerevole consenso tra gli esperti di climatologia e meteorologia. Non mancano però controversie sul cambiamento climatico nel mondo politico, sui media generalisti e nell’opinione pubblica, spesso alimentate da esperti dissidenti. Della questione del riscaldamento globale hanno iniziato a occuparsi da qualche tempo anche i sociologi, partendo dalle proprie competenze specifiche. Utilizzando strumenti scientometrici, questo articolo cerca di stabilire a che titolo e in che misura i sociologi studiano il fenomeno del cambiamento climatico, prestando particolare attenzione ai mutamenti di trend.
... Due to the existence of a self-delivering equilibrium process among carbonate components, surface water has a certain buffering capacity in terms of absorbed CO 2 (Eq. (6); Broecker et al., 1979;Revelle and Suess, 1957). This capacity can be calculated using Eq. ...
Article
The mining of medium- to high‑sulfur coal in karst areas has led to serious acidification problems in surface water, thus encouraging a re-evaluation of DIC transformation and CO2 source-sink relationships in karst watersheds. The weathering of limestone and sulfide-rich coal measures jointly influence the pH of the Huatan River in karst areas in Southwest China, which is lower in the rainy season and higher in the dry season. Due to CO2 degassing, DIC concentration tends to decrease along the flow direction, while δ¹³C-DIC gradually becomes heavier. In general, DIC transformation in the Huatan River is controlled by AMD input, CO2 degassing, organic matter (OM) degradation, and the dissolution and precipitation balance of carbonate minerals in different seasons. In spring, the mineralization of OM from terrestrial and domestic sewage gradually enhances and replenishes DIC in the water. As the pH increases in this season, the capacity for buffering CO2 increases. Meanwhile, OM degradation generates a large amount of CO2 in summer, and carbonic acid begins to dissolve limestone. In autumn, the pH decreases due to the enhanced weathering of sulfide-rich coal measures and the mass input of AMD. Thus, the river shows the ability to drive CO2 outgassing. In winter, CO2 degassing gradually weakens, DIC concentration is at its lowest, and δ¹³C-DIC reaches the heaviest value.
... Another relevant precaution is the need to correct for isotopic values following temporal variations in the isotopic constitution of ecosystems and the atmosphere. The Suess effect represents a change in δ 13 C values in the atmosphere over the years, as a result of an increase in CO 2 from anthropogenic activities (Revelle and Suess 1957), and it should be considered in studies that aim to analyze historical biological data (Dombrosky 2020). ...
Article
Full-text available
Although stable isotopes have been increasingly used in ornithology since 1980 in many places, Brazil has been slow in adopting this methodology, especially when it comes to terrestrial birds. The most common elements in bird ecology studies are carbon, nitrogen, hydrogen, and oxygen stable isotopes, which provide information on diet, trophic interactions, habitat use, migration, geographic patterns, and physiology. It is important that Brazilian ornithologists become aware of the potential of stable isotope analysis in ecological studies, and the shortcomings of this tool. The use of stable isotopes to study bird ecology has great potential in Brazil, since many ecological questions about Neotropical birds can be addressed by it (e.g., resource and habitat use, migratory routes, isotopic niches, anthropogenic impacts, individual specialization). Brazilian museums and other Natural History collections can provide samples to study long-term temporal dynamics in bird ecology. Additionally, the integration of avian tissue sample information into a database may increase the collaboration among researchers and promote sample reuse in a variety of studies. All biomes in Brazil have been under pressure from anthropogenic impacts (e.g., land-use change, habitat loss, fragmentation, intensive agriculture), affecting several taxa, including terrestrial birds. Considering the negative effects of human expansion over natural areas and that stable isotopes provide useful ecological information, ornithologists in Brazil should increase their use of this tool in the future. KEY WORDS: δ13C; δ15N; δ2H; δ18O; migratory birds; museum specimens; ornithology; trophic ecology
... The uncertainty regarding bomb yield has been discussed by Hesshaimer, V. et al. 1994. (Revelle & Suess 1957, Arnold & Anderson 1957, with both papers using a linear description. However these papers subsequently were criticised for overlooking the effects of ocean vertical mixing. ...
Preprint
Whereas many carbon cycle models track CO2 perturbations relative to a pre-industrial equilibrium, this paper uses absolute quantities to describe atmospheric CO2 sinks, source and flow rates. This method, when combined with the notion of source and sink resistance, and a finite biospheric reservoir, accurately describes 14C levels between 1820 and 2020 using only five external parameters. The inputs are:- global records of fossil-fuel emissions, records of CO2 mixing-ratio and listings of atmospheric atomic weapons tests. Over the same period 13C flows are also accurately described given a ð13C value for fossil fuel and a ð13C value for the initial background. This top-down approach differs from complex climate models since it circumvents the necessity to catalogue individual processes. The paper proceeds to use the method to examine the anthropogenic fossil-fuel emissions contributions during the period 1750 to 2020, deducing that around 24% remains in the atmosphere, while 76% has been absorbed in the land, terrestrial biosphere and surface ocean. During the same period 13% of the total CO2 atmospheric concentration is due to fossil fuels. However, regarding the increase, fossil fuels contributed to 38% of the rise during this period.
... Papers published since the 1930s and dealing with the carbon dioxide theory of climate change (Callendar, 1938;Plass, 1956;Revelle & Suess, 1957) and effects of various parameters (e.g.. ocean currents, solar cycles) on the mean temperature of the atmosphere (Manabe, 1969;Stommel, 1961;Walker & Bliss, 1932). Budyko (1969) is not directly related to global warming. ...
Preprint
Full-text available
RPYS is a bibliometric method originally introduced in order to reveal the historical roots of research topics or fields. RPYS does not identify the most highly cited papers of the publication set being studied (as is usually done by bibliometric analyses in research evaluation), but instead it indicates most frequently referenced publications - each within a specific reference publication year. In this study, we propose to use the method to identify important researchers, institutions and countries in the context of breakthrough research. To demonstrate our approach, we focus on research on physical modeling of Earth's climate and the prediction of global warming as an example. Klaus Hasselmann and Syukuro Manabe were both honored with the Nobel Prize in 2021 for their fundamental contributions to this research. Our results reveal that RPYS is able to identify most important researchers, institutions, and countries. For example, all the relevant authors' institutions are located in the USA. These institutions are either research centers of two US National Research Administrations (NASA and NOAA) or universities: the University of Arizona, Princeton University, the Massachusetts Institute of Technology (MIT), and the University of Stony Brook.
... According to the law of thermodynamics, any significant increase in the natural volume and mixture of these gases in the earth's atmosphere may cause the temperature to rise. Climate scientists started suspecting such a rise in temperature during the 1950s and simultaneously, a rise in the level of CO 2 was also detected on the earth's surface (Plass, 1956;Revelle and Suess, 1957). ...
Thesis
Full-text available
The study analyzes the CRU TS panel data of temperature and precipitation reported monthly since 1901 and estimates that the mean surface temperature of the earth has increased by ≈1.00◦C since 1901-1930. However, the global precipitation volume remains unchanged. The CRU TS is merged with the WDI panel data that provides artificial emissions of greenhouse gases from fossil fuels combustion and economic activities for the interval 1970-2018. The study estimates multiple climate change models using pooled OLS specifications and detects methane, liquid fuels, and agricultural activities as the most dominant contributors to global climate change
... By reacting away aqueous CO 2 (equation (3.3)) additional CO 2 can be removed from the atmosphere. This buffering capacity was formalised by Revelle & Suess [95], into what has subsequently been termed the 'Revelle Factor' (RF, equation (3.4)). ...
Article
Soils play an important role in mediating chemical weathering reactions and carbon transfer from the land to the ocean. Proposals to increase the contribution of alkalinity to the oceans through ‘enhanced weathering’ as a means to help prevent climate change are gaining increasing attention. This would augment the existing connection between the biogeochemical function of soils and alkalinity levels in the ocean. The feasibility of enhanced weathering depends on the combined influence of what minerals are added to soils, the formation of secondary minerals in soils and the drainage regime, and the partial pressure of respired CO 2 around the dissolving mineral. Increasing the alkalinity levels in the ocean through enhanced weathering could help to ameliorate the effects of ocean acidification in two ways. First, enhanced weathering would slightly elevate the pH of drainage waters, and the receiving coastal waters. The elevated pH would result in an increase in carbonate mineral saturation states, and a partial reversal in the effects of elevated CO 2 . Second, the increase in alkalinity would help to replenish the ocean's buffering capacity by maintaining the ‘Revelle Factor’, making the oceans more resilient to further CO 2 emissions. However, there is limited research on the downstream and oceanic impacts of enhanced weathering on which to base deployment decisions. This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.
... it was not until 1957 that the link between greenhouse gases and atmospheric and oceanographic temperatures was proven (Revelle and Suess, 1957). Greenhouse gases absorb thermal radiation which is emitted from the Earth's surface, therefore trapping this thermal radiation (EPA, 2015). ...
Thesis
Full-text available
Despite anthropogenically induced climate change being viewed by many as one of the greatest societal challenges of the 21st century, discernment from the public, especially young people, remains under explored within the mitigation debate. This is surprising given research demonstrating the potential for collective action to reduce greenhouse gas emissions nationally through individual behaviour changes. Young people are those in society that will live with the effects of future climate change the longest but are typically overlooked in forward planning. Consequently, this PhD thesis aims to provide detailed understanding of intersecting perception of climate change and levels of engagement being undertaken to explore how people, particularly the young, are reacting to climate change. The nexus of these themes was explored using a mixed method approach through the use of primary data collection, including interviews (N = 5), two national surveys (N = 1,134, survey 1 and N = 1,700, survey 2) and a participatory workshop using the Yonmenkaigi System Method approach (N = 16). In addition, this primary data is cross-analysed through the use of secondary data (BEIS and Eurobarometer) to extrapolate a more comprehensive picture based on the case of the United Kingdom. The research found that in the United Kingdom (and implicitly elsewhere) there are high-levels of perception of climate change as a major concern, especially amongst young people, and more extensively since 2013 when a social tipping point around this issue occurred. This has occurred despite of the ‘finite pool of worry’, a theory suggesting a likely plateauing or decline in concern when other crises start to predominate in people’s day to day, such as during the aftermath of the Brexit vote, COVID-19 and associated economic uncertainty. In terms of youth and perception, this thesis found that whilst young people were the most likely to believe a climate change was happening and most likely to view that climate change is a serious problem, they were one of the least likely group of people to be able to determine what impacts were already being felt within the United Kingdom due to climate change. Although there is this high level of belief in climate change amongst young people and civil society more widely, the level of engagement through mitigation strategies varies. Those strategies that are behavioural are generally undertaken, especially among the youngest in society and those who view climate change as serious. However, this applies when there is substantive investment. This demonstrates that if the government wants to implement significant change through the will of society to reduce greenhouse gas emissions, investment for those on low incomes is needed to enable the requisite behaviour change needed. This research also confirms a view, as iterated by many of its respondents, that education on climate change within the United Kingdom is lacking; application of participatory methods, such as the Yonmenkaigi System Method, demonstrated how education would progress the interconnection between perception and engagement. This study recognises complexity involved in the interconnection between perception, engagement and reaction. However, it is argued that if social media generates fake news especially around climate change, then young people who are the most personal users of social media should be the most exposed. The results show that they are the most believing of climate change and that it is likely social media self-reinforces consistent beliefs through echo chambers. Into the current lacuna of action by the government during this PhD research period, climate activism groups of ‘Extinction Rebellion’ and ‘School Strikes for Climate Change’ materialised. It is argued that the actions of these groups are a form of ‘post-normal engagement’, where people apply their understanding, and that arises through a lack of facilitation of ‘post-normal science’ in relation to climate change within the United Kingdom. It was found that the majority of survey respondents were overall supportive of “Extinction Rebellion”. In addition, it was found that there was also a majority of support for the children striking for climate change and the mass civil disobedience that “Extinction Rebellion” called for in London in April 2019, though at varying levels across the demographic. However, respondents were generally not willing to themselves join future “Extinction Rebellion” protests. Women, younger people and left-leaning voters were more likely to support these two types of protests. The monitoring of the demographic composition of climate protests in terms of perception and engagement drivers helps to assess the nature of likely reactions and resistance to future climate policy including that associated with the content of COP26 being hosted in the UK during 2021. However, the implementation of a post-normal climate change science might help reduce the need for climate activism.
... The projected socioeconomic impact of increasing CO 2 levels in the near future is detrimental, 9 and immediate global actions must be taken to mitigate the threats as we have already passed the threshold level (i.e., 350 ppm) of CO 2 in the atmosphere; the current CO 2 level in the atmosphere is 415 ppm, according to the Mauna Loa Observatory. 10 The imminent danger of ever-rising CO 2 levels was first pinpointed by scientists in the 1950s, but policy makers were not convinced to take stern action to control anthropogenic emission until the late 1990s, 11 especially that coming from burning coal, oil, and natural gases. However, global commitments, such as the Kyoto Protocol and Paris Agreement, have fueled the movement, and as a result, CCUS technologies were introduced, aiming to achieve net-zero greenhouse gas emission by 2050. ...
... Once dissolved in the ocean, CO 2 reacts with water to form a weak acid that loses a hydrogen ion, which is largely neutralized through reaction with a carbonate ion to form bicarbonate, causing the seawater [H + ] to increase and the pH to decrease (Millero, 2007). This overall process is commonly referred to as ocean acidification (Caldeira and Wickett, 2003;Doney et al., 2009), and it may have far reaching effects on marine life (Boyd et al., 2016;Doney et al., 2014;Hofmann et al., 2010;Kleypas et al., 2006) and on the rates of a variety of carbon cycle feedback processes within the ocean (e.g., Archer et al., 1998;Boudreau et al., 2018;Passow and Carlson, 2012;Revelle and Suess, 1957). As a result, it has become a priority in oceanography to monitor ocean pH and understand its natural and anthropogenic variations (Brewer, 2013). ...
Article
Full-text available
The number and quality of ocean pH measurements have increased substantially over the past few decades such that trends, variability, and spatial patterns of change are now being evaluated. However, comparing pH changes across domains with different initial pH values can be misleading because a pH change reflects a relative change in the hydrogen ion concentration ([H+], expressed in mol kg−1) rather than an absolute change in [H+]. We recommend that [H+] be used in addition to pH when describing such changes and provide three examples illustrating why.
... Aerobic net community metabolism impacts primarily TCO 2 , with much smaller impact on alkalinity, and thus carries an implied pCO 2 and TCO 2 covariance. For T ∼ 12 • C, S ∼ 33, the relative change in pCO 2 is 12 times the relative change of TCO 2 [Revelle Factor of 12 (Revelle and Suess, 1957;Broecker et al., 1979;Sundquist et al., 1979)], for all other variables constant. Relative variability in pCO 2 daily minimum and maximum for the intervals depicted ranges 10-20 times that for TCO 2 , adding support to the idea that net metabolism, modulated by diel insolation cycles, is the primary driver of summertime bay carbonate-system variability. ...
Article
Full-text available
Netarts Bay is a shallow, temperate, tidal lagoon located on the northern coast of Oregon and the site of the Whiskey Creek Shellfish Hatchery (WCSH). Data collected with an autonomous continuous flow-through system installed at WCSH capable of high-resolution (1 Hz) partial pressure of aqueous CO2 (pCO2) and hourly total dissolved inorganic carbon (TCO2) measurements, with combined measurement uncertainties of < 2.0% and 0.5%, respectively, is analyzed over the 2014–2019 interval. Summer upwelling, wintertime downwelling, and in situ bay biogeochemistry represent significant modes of the observed variability in carbonate system dynamics. Summer upwelling is associated with large amplitude diel pCO2 variability, elevated TCO2 and alkalinity, but weak variability in salinity. Wintertime downwelling is associated with bay freshening by both local and remote sources, a strong tidal signature in salinity, TCO2, and alkalinity, with diel pCO2 variability much less amplified when compared to summer. Further, analysis of alkalinity-salinity relationships suggests multiple water masses inhabiting the bay during 1 year: mixing of end-members associated with direct precipitation, coastal rivers, southward displacement of the Columbia River plume, California Current surface and deep upwelled waters. The importance of in-bay processes such as net community metabolism during intervals of high productivity are apparent. These direct measurements of pCO2 and TCO2 have been useful to local hatchery owners who have monitored intake waters following historic seed-production failures related to high-CO2 conditions exacerbated by ocean acidification.
... reacts with water to form a weak acid that loses a hydrogen ion, which is largely neutralized through reaction with 50 carbonate ion to form bicarbonate, causing the seawater [H + ] to increase and the pH to decrease (Millero, 2007). This overall process is commonly referred to as ocean acidification (Caldeira and Wickett, 2003;Doney et al., 2009), and may have far reaching effects on marine life (Boyd et al., 2016;Doney et al., 2014;Hofmann et al., 2010;Kapsenberg and Cyronak, 2019;Kleypas et al., 2006;McNeil and Sasse, 2016;Orr et al., 2005) and on the rates of a variety of carbon cycle feedback processes within the ocean (e.g., Archer et al., 1998;Boudreau et al., 2018;Passow and Carlson, 55 2012; Revelle and Suess, 1957). As a result, it has become a priority in oceanography to monitor ocean pH and understand its natural and anthropogenic variations (Brewer, 2013). ...
Preprint
Full-text available
The number and quality of ocean pH measurements has increased substantially over the past few decades such that trends, variability, and spatial patterns of change are now being evaluated. However, comparing pH changes across domains with different initial pH values can be misleading because a pH change reflects a relative change in the hydrogen ion concentration ([H+]–expressed in mol kg−1) rather than an absolute change in [H+]. We recommend that [H+] be used in addition to pH when describing such changes and provide three examples illustrating why.
... Here, we calculated the Revelle factor (R), which is the ratio of instantaneous change in pCO 2 to the change in DIC (Revelle and Suess, 1957); Δ[DIC] at ΔpCO 2 = 1 is calculated using CO2SYS with the assumption of Δ[TA] = 0 (Broecker et al. 1979). Climatological means are used for pCO 2 , [DIC] and other parameters. ...
Article
Full-text available
A compilation of surface water nutrient (phosphate, nitrate, and silicate) and partial pressure of CO2 (pCO2) observations from 1961 to 2016 reveals seasonal and interannual variability in the North Pacific. Nutrients and calculated dissolved inorganic carbon (DIC) reach maximum concentrations in March and minimum in August. Nutrient and DIC variability is in-phase (anti-phase) with changes in the mixed layer depth (sea surface temperature) north of 30 °N, and it is anti-phase (in-phase) with changes in Chl-a north of 40 °N (in 30 °N–40 °N). Seasonal drawdown of nutrients and DIC is larger toward the northwest and shows a local maximum in the boundary region between the subarctic and subtropics. Stoichiometric ratios of seasonal drawdown show that, compared to nitrate, silicate drawdown is large in the northwestern subarctic including the Bering and Okhotsk seas, and drawdown of carbon is larger toward the south. Net community production in mixed layer from March to July is estimated to be more than 6 gC/m2/mo in the boundary region between the subarctic and subtropics, the western subarctic, the Gulf of Alaska, and the Bering Sea. Nutrient and DIC concentrations vary with the Pacific Decadal Oscillation and the North Pacific Gyre Oscillation which cause changes in horizontal advection and vertical mixing. The DIC trend is positive in all analysis area and large in the western subtropics (> 1.0 μmol/l/yr). Averaged over the analysis area, it is increasing by 0.77 ± 0.03 μmol/l/yr (0.75 ± 0.02 μmol/kg/yr).
Preprint
Although nett CO2 flows can be estimated with reasonable accuracy, the contributing gross fluxes between the atmosphere and the earth's surface are poorly understood. This paper presents a means by which the global outflow and inflow of CO2 between atmosphere and "mixing reservoirs" can be calculated, using the radiocarbon isotopes 14CO2 and 13CO2 as a tracer. It has been asserted that isotopic CO2 cannot be directly used as a tracer in flow studies because Δ14C is not subject to the Revelle factor; evidence is provided showing that this view is mistaken. The model contains 7 key parameters which are used to provide outputs of Δ14C and d13C as a function of time. By optimising the fit of these two outputs with historical records spanning 200 years or more, including during the bomb pulse, the key parameters are determined. The quality of fit of Δ14C and d13C is excellent and the internal parameters optimise at reasonable values. The global flux to and from the effective mixing reservoir, whose size is six times that of the atmosphere, is currently 58 GTC/yr in 2020, not including annually cycled carbon.
Preprint
Full-text available
Ocean alkalinity is critical to the uptake of atmospheric carbon in surface waters and provides buffering capacity towards associated acidification. However, unlike dissolved inorganic carbon (DIC), alkalinity is not directly impacted by anthropogenic carbon emissions. Within the context of projections of future ocean carbon uptake and potential ecosystem impacts, especially through Coupled Model Intercomparison Projects (CMIPs), the representation of alkalinity and the main driver of its distribution in the ocean interior, the calcium carbonate cycle, have often been overlooked. Here we track the changes from CMIP5 to CMIP6 with respect to the Earth system model (ESM) representation of alkalinity and the carbonate pump which depletes the surface ocean in alkalinity through biological production of calcium carbonate, and releases it at depth through export and dissolution. We report a significant improvement in the representation of alkalinity in CMIP6 ESMs relative to those in CMIP5. This improvement can be explained in part by an increase in calcium carbonate (CaCO3) production for some ESMs, which redistributes alkalinity at the surface and strengthens its vertical gradient in the water column. We were able to constrain a PIC export estimate of 51–70 Tmol yr-1 at 100 m for the ESMs to match the observed vertical gradient of alkalinity. Biases in the vertical profile of DIC have also significantly decreased, especially with the enhancement of the carbonate pump, but the representation of the saturation horizons has slightly worsened in contrast. Reviewing the representation of the CaCO3 cycle across CMIP5/6, we find a substantial range of parameterizations. While all biogeochemical models currently represent pelagic calcification, they do so implicitly, and they do not represent benthic calcification. In addition, most models simulate marine calcite but not aragonite. In CMIP6 certain model groups have increased the complexity of simulated CaCO3 production, sinking, dissolution and sedimentation. However, this is insufficient to explain the overall improvement in the alkalinity representation, which is therefore likely a result of improved marine biogeochemistry model tuning or ad hoc parameterizations. We find differences in the way ocean alkalinity is initialized that lead to offsets of up to 1 % in the global alkalinity inventory of certain models. These initialization biases should be addressed in future CMIPs by adopting accurate unit conversions. Although modelers aim to balance the global alkalinity budget in ESMs in order to limit drift in ocean carbon uptake under preindustrial conditions, varying assumptions in the closure of the budget have the potential to influence projections of future carbon uptake. For instance, in many models, carbonate production, dissolution and burial are independent of the seawater saturation state, and when considered, the range of sensitivities is substantial. As such, the future impact of ocean acidification on the carbonate pump, and in turn ocean carbon uptake, is potentially underestimated in current ESMs and insufficiently constrained.
Thesis
Cette thèse a pour objet d’interroger la singularité historique du concept d’Anthropocène dans le domaine des sciences de la Terre afin de répondre au problème de savoir à quel titre il peut être considéré comme un événement réflexif de la modernité. Pour ce faire, nous entreprenons une archéologie de ce concept selon trois temporalités. La première, s’étalant du XIXe siècle au début du XXe siècle, interroge le statut des énoncés savants caractérisant l’influence globale de l’agir humain. Il apparaît que l’activité géologique de l’humanité était déjà au cœur des sciences modernes. La temporalité intermédiaire de la deuxième partie montre comment le discours géologique est profondément renouvelé après la Seconde Guerre mondiale. La Terre est alors réinventée comme un environnement total au sein d’un dispositif de savoir et de pouvoir. Enfin, la troisième partie, en temporalité courte, analyse le processus de fabrication du concept d’Anthropocène, principalement dans les sciences du système Terre et dans la géologie. Résultant d’associations entre des acteurs aux projets hétérogènes, ce processus oscille entre une dynamique d’extension et une dynamique de spéciation du concept dans les normes de la géologie, qui sont bousculées par l’actualité de l’Anthropocène. Au bilan, il ressort que ce concept s’inscrit dans le long héritage du dire géologique de la modernité, mais le renouvelle profondément. L’actualité géologique définie comme une pathologie dessine en creux une norme de santé de la Terre que la politique doit s’approprier.
Preprint
Full-text available
Blue carbon ecosystems provide a wide range of ecosystem services, are critical in maintaining marine biodiversity, and may potentially serve as sites of economically viable carbon dioxide removal through enhanced organic carbon storage. Here we show that restoring two key blue carbon ecosystems — mangroves and seagrasses — will also foster high rates of permanent atmospheric carbon dioxide removal (potentially up to ~10 tCO2 ha-1 year-1) by driving ocean alkalinity enhancement.
Article
Plazas are ubiquitous elements of community layout, defined as open space surrounded by or adjacent to structures. Functionally, plazas serve as public space for gatherings and ceremonial activities. At Cahokia Mounds, the largest pre-contact site in North America, the North Plaza puzzled archaeologists because of its unique location in a wetland. The construction of a mound and plaza group in an area inundated with water is unprecedented in the Eastern-Woodlands archaeological record and contradicts traditional conceptions of plaza space. Previous scholars dealt with this conundrum by hypothesizing that the North Plaza was drier during its construction and occupation than in modern times. However, evidence from sedimentological analysis and stable carbon isotopes of buried soils suggests the North Plaza was an inundated feature on the landscape throughout Cahokia’s occupation. The North Plaza is an anomaly in the Eastern-Woodlands that now requires archaeologists to re-envision what plazas are and how they are used.
Article
Full-text available
Observations and climate models indicate that changes in the seasonal amplitude of sea surface carbon dioxide partial pressure (A‐pCO2) are underway and driven primarily by anthropogenic carbon (Cant) accumulation in the ocean. This occurs because pCO2 is more responsive to seasonal changes in physics (including warming) and biology in an ocean that contains more Cant. A‐pCO2 changes have the potential to alter annual ocean carbon uptake and contribute to the overall marine carbon cycle feedback. Using the GFDL ESM2M Large Ensemble and a novel analysis framework, we quantify the influence of Cant accumulation on pCO2 seasonal cycles and sea‐air CO2 fluxes. Specifically, we reconstruct alternative evolutions of the contemporary ocean state in which the sensitivity of pCO2 to seasonal thermal and biophysical variation is fixed at preindustrial levels, however the background, mean‐state pCO2 fully responds to anthropogenic forcing. We find near‐global A‐pCO2 increases of >100% by 2100, under RCP8.5 forcing, with rising Cant accounting for ∼100% of thermal and ∼50% of nonthermal pCO2 component amplitude changes. The other ∼50% of nonthermal pCO2 component changes are attributed to modeled changes in ocean physics and biology caused by climate change. Cant‐induced A‐pCO2 changes cause an 8.1 ± 0.4% (ensemble mean ± 1σ) increase in ocean carbon uptake by 2100. The is because greater wintertime wind speeds enhance the impact of wintertime pCO2 changes, which work to increase the ocean carbon sink. Thus, the seasonal ocean carbon cycle feedback works in opposition to the larger, mean‐state feedback that reduces ocean carbon uptake by ∼60%.
Article
Full-text available
We still do not know, where the Planetary boundary for novel entities lies, but we have probably crossed it! Persson et al. argue that we are outside the safe operating space of the planetary boundary for novel entities, since the annual production and releases of chemicals including plastics are increasing at a pace that outstrips the global capacity for assessment and monitoring. This is, however, not a planetary boundary, but a societal boundary. A measure of the ability or inability of chemical screening to keep at pace with the introduction of new chemicals and their mixtures.
Chapter
Full-text available
We give a plain language guide to the Earth’s carbon cycle by briefly summarising the observations and origins of increased levels of greenhouse gases, mainly CO2 but including CH4 and N2O, in our present-day atmosphere. They are increased in the sense that they have not occurred naturally in the Earth’s atmosphere at any time during the past 420,000 years. The only tenable explanation for our atmosphere’s present state is that it is the consequence of mankind’s excessive use of fossil fuels since the Industrial Revolution onwards.
Article
Full-text available
Climate models are what governments, experts and societies base their decisions on future climate action on. To show how different models were used to explain climatic changes and to project future climates before the emergence of a global consensus on the validity of general circulation models, this article focuses on the attempt of Soviet climatologists and their government to push for their climate model to be acknowledged by the international climate science community. It argues that Soviet climate sciences as well as their interpretations of the climate of the twenty-first century were products of the Cold War, and that the systematic lack of access to high-speed computers forced Soviet climatologists to use simpler climate reconstructions as analogues, with far-reaching consequences for climate sciences in post-Soviet Russia. By juxtaposing the history of Soviet climate modelling with the early history of the Intergovernmental Panel for Climate Change, which rejected the Soviet model, the article sheds light on the relationship of science and politics. The findings are based on archival and print material as well as on interviews.
Article
Full-text available
Ocean acidification is changing surface water chemistry, but natural variability due to nearshore processes can mask its effects on ecosystem responses. We present an approach of quantitatively resolving net ecosystem metabolism from an array of long‐term time series stations, offering perhaps the longest record of such processes over a reef to date. We used 8 and 6 yr of in situ, high‐quality frequency observations to characterize the changes in dissolved inorganic carbon and oxygen in La Parguera, Puerto Rico and Cheeca Rocks, Florida, respectively. Net respiration and net dissolution are the dominant metabolic processes at both systems, with a narrow window of ~ 4 months under net calcification. The annual mean net ecosystem calcification (NEC) rates for La Parguera (−0.68 ± 0.91 kg CaCO3 m−2 yr−1) and Cheeca Rocks (−0.48 ± 0.89 kg CaCO3 m−2 yr−1) were on the lower end of typical NEC ranges determined for other reef areas using chemistry‐ and census‐based approaches. At Cheeca Rocks, 53% of the variance in NEC can be explained by net ecosystem production (NEP) and 30% by aragonite saturation state (Ωarag). At La Parguera, NEC is primarily driven by changes in NEP. The linear relationship between NEC and NEP showed a significant slope (± standard error) of 1.00 ± 0.005 and 0.88 ± 0.04 for La Parguera and Cheeca Rocks, respectively. These results suggest that NEP appears to play a prominent role on NEC, and Ωarag probably is not the most informative measure to monitor when attempting to resolve the long‐term impacts of ocean acidification.
Article
Full-text available
Large amounts of the carbon‐isotope ¹⁴C, entering Earth's carbon cycle, were produced in the atmosphere by atomic bomb tests in the 1950s and 1960s. Here, we forced the ocean and land components of the Community Earth System Model with atmospheric ¹⁴CO2 over the historical period to constrain overturning time scales and fluxes. The uptake of bomb ¹⁴C by the land model is lower than observation‐based estimates. This mismatch is likely linked to too‐low ¹⁴C uptake by vegetation as the model overestimates ¹⁴C/C ratios of modern soils. This suggests model biases in forest productivity or wood carbon allocation and turnover, and, in turn, a bias in the forest sink of anthropogenic carbon. The ocean model matches the observation‐based global bomb ¹⁴C inventories when applying the quadratic relationship between gas transfer piston velocity and wind speed of Wanninkhof (2014), https://doi.org/10.4319/lom.2014.12.351 and the wind products from Large and Yeager or the Japanese Reanalysis Project. Simulated natural radiocarbon ages in the deep ocean are many centuries older than data‐based estimates, indicating too slow deep ocean ventilation. The sluggish circulation causes large biases in biogeochemical tracers and implies a delayed deep ocean uptake of heat and carbon in global warming projections. Our study suggests that ¹⁴C observations are key to constrain carbon fluxes and transport timescales for improved representations of land and ocean biogeochemical cycles and Earth system model projections.
Article
Full-text available
Climate impacts are not always easily discerned in wild populations as detecting climate change signals in populations is challenged by stochastic noise associated with natural climate variability, variability in biotic and abiotic processes, and observation error in demographic rates. Detection of the impact of climate change on populations requires making a formal distinction between signals in the population associated with long-term climate trends from those generated by stochastic noise. The time of emergence (ToE) identifies when the signal of anthropogenic climate change can be quantitatively distinguished from natural climate variability. This concept has been applied extensively in the climate sciences, but has not been explored in the context of population dynamics. Here, we outline an approach to detecting climate-driven signals in populations based on an assessment of when climate change drives population dynamics beyond the envelope characteristic of stochastic variations in an unperturbed state. Specifically, we present a theoretical assessment of the time of emergence of climate-driven signals in population dynamics (ToEpop). We identify the dependence of ToEpop on the magnitude of both trends and variability in climate and also explore the effect of intrinsic demographic controls on ToEpop. We demonstrate that different life histories (fast species vs. slow species), demographic processes (survival, reproduction) and the relationships between climate and demographic rates, yield population dynamics that filter climate trends and variability differently. We illustrate empirically how to detect the point in time when anthropogenic signals in populations emerge from stochastic noise for a species threatened by climate change: the emperor penguin. Finally, we propose six testable hypotheses and a road map for future research.
Article
Full-text available
The intensification of land-use changes in tropical forests during the 20th century, mainly caused by deforestation for agricultural uses, had an overwhelming influence on bird assemblages. However, how these historical anthropogenic changes have impacted the habitat use and diet of tropical birds is poorly known. Stable isotope analysis (δ 13 C and δ 15 N) can be useful in this regard since it provides information not only on the habitat and food resource use but also insights on the dietary niche of species. Here, we aimed to evaluate whether centenary anthropogenic impacts, mainly caused by changes in landscape composition, have affected the resource and habitat use and isotopic niche width of Neotropical birds in a region that comprises two biodiversity hotspots-the Atlantic Forest and Cerrado in southeastern Brazil. We found that the niche width of all bird guilds (frugivore, granivore, insectivore, nectarivore and omnivore) was largely reduced (28-70%) from the 20th century until recently. This niche width reduction was likely associated with historical anthropogenic impacts (e.g. fragmentation, forest loss and change in agricultural practices), which are responsible for the decrease in the availability of habitat and food resources. Moreover, the mean values of δ 15 N decreased over the years in all bird guilds, which might be attributed to the expansion of agricultural areas and the increase in the use of synthetic nitrogen based fertilizers. All the analyzed species, even though some of them are diet and habitat generalists, were strongly influenced by centenary anthropogenic actions. Our results show the consequences of human-induced changes in land use on the diet and habitat use of tropical birds that persist in fragmented landscapes, which might compromise their long-term survival and provide useful information to the conservation strategies of bird assemblages in modern landscapes.
Article
Full-text available
Significance Anthropogenic lead (Pb) is widespread and far reaching in the environment. However, it was thought that western Arctic Ocean seawater was pristine based on low dissolved Pb and proxy data. By measuring Pb isotopes on seawater with extremely low concentrations, this study shows that anthropogenic Pb is pervasive in western Arctic Ocean seawater, and much of the dissolved Pb is from remobilization of previously deposited aerosols from the high-Pb emission period of the 20th century. Thus, historic Pb pollution still impacts Arctic seawater, and accelerated melting of permafrost and ice and increased coastal erosion may enhance this remobilization. This study also demonstrates that dissolved Pb isotopes are a sensitive tracer of contaminant and particulate sources in Arctic seawater.
Article
Full-text available
Deforestation and habitat loss resulting from land use changes are some of the utmost anthropogenic impacts that threaten tropical birds in human-modified landscapes (HMLs). The degree of these impacts on birds’ diet, habitat use, and ecological niche can be measured by isotopic analysis. We investigated whether the isotopic niche width, food resources, and habitat use of bird trophic guilds differed between HMLs and natural landscapes (NLs) using stable carbon (δ13C) and nitrogen isotopes (δ15N). We analyzed feathers of 851 bird individuals from 28 landscapes in the Brazilian Atlantic Forest. We classified landscapes into two groups according to the percentage of forest cover (HMLs ≤ 30%; NLs ≥ 47%), and compared the isotopic niche width and mean values of δ13C and δ15N for each guild between landscape types. The niches of frugivores, insectivores, nectarivores, and omnivores were narrower in HMLs, whereas granivores showed the opposite pattern. In HMLs, nectarivores showed a reduction of 44% in niche width, while granivores presented an expansion of 26%. Individuals in HMLs consumed more resources from agricultural areas (C4 plants), but almost all guilds showed a preference for forest resources (C3 plants) in both landscape types, except granivores. Degraded and fragmented landscapes typically present a lower availability of habitat and food resources for many species, which was reflected by the reduction in niche width of birds in HMLs. Therefore, to protect the diversity of guilds in HMLs, landscape management strategies that offer birds more diverse habitats must be implemented in tropical regions.
Chapter
Full-text available
Radiocarbon dating is the most widely applied dating technique for understanding past mangrove environments and dynamics. Mangrove sediments contain an abundance of different carbon sources for radiocarbon dating. Creating reliable chronologies, however, is challenging, largely due to contamination from modern root systems. Radiocarbon ages derived from bulk sediments are difficult to link exactly to past environmental changes or events because they are mean ages of an unknown mix of carbon sources. Aboveground surface macrofossil samples and methods that concentrate specific size fractions (e.g., pollen concentrates) will likely provide more control on possible carbon sources and more reliable ages. Ultimately, it is important to carefully consider stratigraphy and likely depositional environments of mangrove sedimentary records to provide the necessary sample context.
Article
Full-text available
Seagrass is a water plant that has flowers and ability to adapt to live and grow in the sea like a terrestrial plant. The survival of seagrass is greatly influenced by physical and chemical parameters of waters, such as pH, temperature, and salinity. The Intergovernmental Panel on Climate Change (IPCC) report by the end of 21st century, CO2 in the atmosphere has doubled along with the industrial development. The increase in CO2 in the atmosphere causes ocean acidification, it can change the chemical structure and decrease the pH of sea water. The low pH of sea water influences plant phisiology such as the inhibition of photosynthesis and growth. The purpose of this study is to examine the effect of pH on the growth and photosynthesis rate of seagrass Thalassia hemprichii. The study used Completely Randomized Design with 3 treatments control (8.10-8.50), medium pH (7.76-8.00) and low pH (7.50-7.75) in 5 replicates. The results showed that growth rate, photosynthetic rate and chlorophyll content has a bigger value on control treatment than the low pH treatment. The ANOVA test results were not significant for all treatment variables and had a negative impact on the survival of seagrass.
Article
Full-text available
To address the climate change caused by anthropogenic emissions of greenhouse gases into the atmosphere, it is essential to understand and quantitatively elucidate their cycling on the Earth’s surface. This paper first presents an overview of the global cycling of three greenhouse gases, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), followed by a description of their variations in the atmosphere. This paper then presents the recent global budgets of these greenhouse gases estimated using two different approaches, top-down and bottom-up. Discussions on our current knowledge regarding the global cycling of the three gases are also presented.
Article
The US is showing ever greater attention to the Arctic as a result of the geopolitical incentives and constraints deriving from climate change – an abrupt change in physical geography. According to major defence documents, the effects of climate change on US national security have intensified in the last few years, threatening even homeland defence. The very fact that the consequences of climate change have been taken into consideration by the Trump administration’s national security planning despite the President’s controversial position on global warming constitutes remarkable proof of the persistent importance of geography for national security.
Article
Set between Sri Lankan independence and the outbreak of civil war, Romesh Gunesekera’s Reef features a marine biologist named Salgado who predicts the decay of the island’s coral exoskeleton, a fragile barrier against inundation by the sea. Critics overwhelmingly view the eroding reef as a symbolic harbinger of the violence that eventually engulfed Sri Lanka. But this essay takes the novel’s motif of dying coral and rising seas more literally, reading Reef as an incipient work of postcolonial Anthropocene fiction. A finalist for the 1994 Booker Prize, Reef preceded a wave of climate novels published by prominent authors after the turn of the millennium. More remarkable, it appeared five years before the first major report linking widespread coral damage to anthropogenic climate change. While Salgado’s research serves as a failed fictional antecedent to these findings, his servant Triton ultimately perceives that carbon emissions are destroying the reef. Indeed, what makes Gunesekera’s novel a postcolonial work of Anthropocene fiction is precisely Triton’s status as a servant. I argue that this status not only enables Triton to perceive the material and social conditions that cause climate change. It also shapes his interspecies perspective, allowing Triton to think and feel like a reef.
Article
Full-text available
As technologies of ocean exploitation emerged during the late 1960s, science policy and diplomacy were formed in response to anticipated capabilities that did not match the realities of extracting deep‐sea minerals and of resource exploitation in the deep ocean at the time. Promoters of ocean exploitation in the late 1960s envisaged wonders such as rare mineral extraction and the stationing of divers in underwater habitats from which they would operate seabed machinery not connected to the turbulent surface waters. Their promises coincided with others' fears that nuclear weaponry would be placed on the seabed. Those who lacked the technological capability to extract minerals from the seabed also had concerns that other nations would exploit their resources. Scientific imaginaries caused uncertainty in the international community—especially in the “Global South.” The UN called the “Law of the Sea” conferences to mediate emerging geopolitical tensions caused by these imaginaries of exploitation of ocean resources. These conferences became a site where lawmakers projected futures rather than merely responding to past or present dilemmas. Diplomats' negotiations, with their basis in anticipation of the future uses of science and technology, reveal the role of scientific imaginaries within complex negotiations. Here, we see the impact of the distinction (or blurring) of the real and the imagined on the balance of relations between Global North and South increasing global imbalances of resources and power. This article's analysis of such scientific diplomacy provides a valuable example of the power of scientific imaginaries to have a global impact.
Article
A discussion is given of a simple mathematical model of the carbon dioxide cycle in atmosphere-biosphere-sea, with special attention to the possibility of self-sustained oscillations and to the behaviour of the cycle when additional carbon dioxide is injected from an outer source. The discussion is confined to phenomena with characteristic times of the order of 10–10 3 years leaving out the long geologic periods as well as the purely annual periods. Some numerical computations are also carried out on the electronic computer BESK. The discussion and the computations show that self-sustained oscillations possibly appear due to the presence of the sea, and that they generally are favoured when there exist time-lags in the biosphere of the order of a few decades. The computations also indicate that additional carbon dioxide injected at a rate corresponding to the present combustion of fossil carbon does not change significantly the carbon dioxide concentration in the atmosphere, since most part of it will be stored in the biosphere. Thus, the present theory suggests that the increase of carbon dioxide indicated by recent measurements may represent part of a natural self-sustained oscillation and not necessarily be a response to an increased combustion of fossils. DOI: 10.1111/j.2153-3490.1956.tb01207.x
Article
The most recent calculations of the infra-red flux in the region of the 15 micron CO 2 band show that the average surface temperature of the earth increases 3.6° C if the CO 2 concentration in the atmosphere is doubled and decreases 3.8° C if the CO 2 amount is halved, provided that no other factors change which influence the radiation balance. Variations in CO 2 amount of this magnitude must have occurred during geological history; the resulting temperature changes were sufficiently large to influence the climate. The CO 2 balance is discussed. The CO 2 equilibrium between atmosphere and oceans is calculated with and without CaCO 3 equilibrium, assuming that the average temperature changes with the CO 2 concentration by the amount predicted by the CO 2 theory. When the total CO 2 is reduced below a critical value, it is found that the climate continuously oscillates between a glacial and an inter-glacial stage with a period of tens of thousands of years; there is no possible stable state for the climate. Simple explanations are provided by the CO 2 theory for the increased precipitation at the onset of a glacial period, the time lag of millions of years between periods of mountain building and the ensuing glaciation, and the severe glaciation at the end of the Carboniferous. The extra CO 2 released into the atmosphere by industrial processes and other human activities may have caused the temperature rise during the present century. In contrast with other theories of climate, the CO 2 theory predicts that this warming trend will continue, at least for several centuries. DOI: 10.1111/j.2153-3490.1956.tb01206.x
Article
The Scandinavian CO 2 -sampling in 1955 is described. The mean results for the calendar year are given. Earlier CO 2 -measurements are discussed and a figure showing most of these values is given. The theory of Callendar is discussed and the Scandinavian values are compared with Callendar's. The seasonal variations at the Scandinavian stations are compared and the results discussed. The possibility of drawing synoptic maps is discussed and one example is shown. The desirability of systematic CO 2 -measurements on a global scale is emphasized. DOI: 10.1111/j.2153-3490.1956.tb01208.x
Article
An approximate distribution of carbon dioxide exchange rates between the atmosphere and the North Atlantic Ocean is obtained for each month of the year on the basis of oceanographic data from Bohnecke's Atlas and the assumption that atmospheric carbon dioxide maintains uniformly the volume percentage of .03. The results indicate the direction in which such an even volume percentage must be changed to approach equilibrium. Aside from other influences, the ocean-atmosphere exchange of carbon dioxide and the trajectories of tropospheric air masses combine to produce high carbon dioxide content in m T and c P air and low carbon dioxide content in m P air. Since water vapor is at a minimum in the continental polar anticyclones during the polar night, the carbon dioxide probably serves as an effective inhibitor of the outgoing infrared radiation. This inhibiting effect may well serve to limit the intensity of cooling during an ice age; it probably has much less significance during inter-glacial periods. DOI: 10.1111/j.2153-3490.1954.tb01129.x
Article
DOI:https://doi.org/10.1103/PhysRev.92.512.2
Article
This list gives details of samples dated in the Nuclear Sciences Laboratory, in the period from June 1956 to July 1958, and follows on from previously published results (Fergusson and Rafter, 1953, 1955, 1957).
Article
The search for causes of the rising temperatures in some geographic areas during the twentieth century has directed interest toward the amount of atmospheric carbon dioxide (GOa). If the carbon dioxide added by the combustion of fossil fuels remains as a net increase, any temperature-changing effects of its presence as a minor constituent of the atmosphere should be cumulatively operative as the amount increases. In this paper, the physical knowledge of atmospheric GO2 is examined and the available nineteenth and twentieth century observations of the atmospheric COa concentration are summarized to ascertain the extent to which they corroborate claims that the amount of atmospheric COa has increased since the nineteenth century. In the light of the uncertainty of both physical knowledge and of statistical analysis, it is concluded that the question of a trend in atmospheric GO, concentration remains an open subject.
Article
An approximate distribution of carbon dioxide exchange rates between the atmosphere and the North Atlantic Ocean is obtained for each month of the year on the basis of oceanographic data from Böhnecke's Atlas and the assumption that atmospheric carbon dioxide maintains uniformly the volume percentage of .03. The results indicate the direction in which such an even volume percentage must be changed to approach equilibrium.Aside from other influences, the ocean-atmosphere exchange of carbon dioxide and the trajectories of tropospheric air masses combine to produce high carbon dioxide content in mT and cP air and low carbon dioxide content in mP air. Since water vapor is at a minimum in the continental polar anticyclones during the polar night, the carbon dioxide probably serves as an effective inhibitor of the outgoing infrared radiation. This inhibiting effect may well serve to limit the intensity of cooling during an ice age; it probably has much less significance during inter-glacial periods.
Article
The first measurements to determine the composition of the atmosphere were made at least 180 years ago, but chemists worked more than a century before they obtained really accurate values for the amount of carbon dioxide in the air.In the following: a brief review is given of the present state of knowledge concerning the variations of atmospheric carbon dioxide, together with some observations which appear to show that the amount of this gas in the air has increased of late years.
Article
The Scandinavian CO2-sampling in 1955 is described. The mean results for the calendar year are given. Earlier CO2-measurements are discussed and a figure showing most of these values is given. The theory of Callendar is discussed and the Scandinavian values are compared with Callendar's. The seasonal variations at the Scandinavian stations are compared and the results discussed. The possibility of drawing synoptic maps is discussed and one example is shown. The desirability of systematic CO2-measurements on a global scale is emphasized.
Article
A discussion is given of a simple mathematical model of the carbon dioxide cycle in atmosphere-biosphere-sea, with special attention to the possibility of self-sustained oscillations and to the behaviour of the cycle when additional carbon dioxide is injected from an outer source. The discussion is confined to phenomena with characteristic times of the order of 10–103 years leaving out the long geologic periods as well as the purely annual periods. Some numerical computations are also carried out on the electronic computer BESK. The discussion and the computations show that self-sustained oscillations possibly appear due to the presence of the sea, and that they generally are favoured when there exist time-lags in the biosphere of the order of a few decades. The computations also indicate that additional carbon dioxide injected at a rate corresponding to the present combustion of fossil carbon does not change significantly the carbon dioxide concentration in the atmosphere, since most part of it will be stored in the biosphere. Thus, the present theory suggests that the increase of carbon dioxide indicated by recent measurements may represent part of a natural self-sustained oscillation and not necessarily be a response to an increased combustion of fossils.
Article
By fuel combustion man has added about 150,000 million tons of carbon dioxide to the air during the past half century. The author estimates from the best available data that approximately three quarters of this has remained in the atmosphere.The radiation absorption coefficients of carbon dioxide and water vapour are used to show the effect of carbon dioxide on “sky radiation.” From this the increase in mean temperature, due to the artificial production of carbon dioxide, is estimated to be at the rate of 0.003°C. per year at the present time.The temperature observations a t zoo meteorological stations are used to show that world temperatures have actually increased at an average rate of 0.005°C. per year during the past half century.
Article
The most recent calculations of the infra-red flux in the region of the 15 micron CO2 band show that the average surface temperature of the earth increases 3.6° C if the CO2 concentration in the atmosphere is doubled and decreases 3.8° C if the CO2 amount is halved, provided that no other factors change which influence the radiation balance. Variations in CO2 amount of this magnitude must have occurred during geological history; the resulting temperature changes were sufficiently large to influence the climate. The CO2 balance is discussed. The CO2 equilibrium between atmosphere and oceans is calculated with and without CaCO3 equilibrium, assuming that the average temperature changes with the CO2 concentration by the amount predicted by the CO2 theory. When the total CO2 is reduced below a critical value, it is found that the climate continuously oscillates between a glacial and an inter-glacial stage with a period of tens of thousands of years; there is no possible stable state for the climate. Simple explanations are provided by the CO2 theory for the increased precipitation at the onset of a glacial period, the time lag of millions of years between periods of mountain building and the ensuing glaciation, and the severe glaciation at the end of the Carboniferous. The extra CO2 released into the atmosphere by industrial processes and other human activities may have caused the temperature rise during the present century. In contrast with other theories of climate, the CO2 theory predicts that this warming trend will continue, at least for several centuries.
Article
Several hundred samples of carbon from various geologic sources have been analyzed in a new survey of the variation of the ratio C13/C12 in nature. Mass spectrometric determinations were made on the instruments developed by H. C. Urey and his co-workers utilizing two complete feed systems with magnetic switching to determine small differences in isotope ratios between samples and a standard gas. With this procedure variations of the ratio C13/C12 can be determined with an accuracy of ±0.01% of the ratio.The results confirm previous work with a few exceptions. The range of variation in the ratio is 4.5%. Terrestrial organic carbon and carbonate rocks constitute two well defined groups, the carbonates being richer in C13 by some 2%. Marine organic carbon lies in a range intermediate between these groups. Atmospheric CO2 is richer in C13 than was formerly believed. Fossil wood, coal and limestones show no correlation of C13/C12 ratio with age. If petroleum is of marine organic origin a considerable change in isotopic composition has probably occurred. Such a change seems to have occurred in carbon from black shales and carbonaceous schists. Samples of graphites, diamonds, igneous rocks and gases from Yellowstone Park have been analyzed. The origin of graphite cannot be determined from C13/C12 ratios. The terrestrial distribution of carbon isotopes between igneous rocks and sediments is discussed with reference to the available meteoritic determinations. Isotopic fractionation between iron carbide and graphite in meteorites may indicate the mechanism by which early fractionation between deep seated and surface terrestrial carbon may have occurred.
Die Löslichkeit von Gasen in Flüssigkeiten
  • Bohr
Natural radiocarbon measurements by acetylene counting Radiocarbon concentration in modern wood 1942: The Oceans World requirements of energy, 197j--zooo
  • H E Sijess
  • H E Suess
  • H U Sverdrup
  • M W Johnson
SIJESS, H. E., 1954: Natural radiocarbon measurements by acetylene counting. Science 120, p. 5. SUESS, H. E., 1955: Radiocarbon concentration in modern wood. Science 122, p. 415. SVERDRUP, H. U., JOHNSON, M. W., and FLEMING, R. H.. 1942: The Oceans. New York: Prentice-Hall, Inc. UNJTED NATIONS, 1955: World requirements of energy, 197j--zooo. International ConJerence on Peaceful Uses $Atomic Energy, Geneva, I, p. 3. UREY, H. C., 1952: The Planets. New Haven: Yale Univ. Press. Tellus 1X (19J7). 1
Carbon dioxide variations in the atmosphere The Chemistry and Fertility of Sea Water Liquid scintillation counting of natural radiocarbon
  • S Fonselius
  • F Koroleff
  • K Warme
  • H W Harvey
  • F N Hayes
  • E C Anderson
FONSELIUS, S., KOROLEFF, F., and WARME, K., 1956: Carbon dioxide variations in the atmosphere. Tellus 8, p. 176. HARVEY, H. W., 1955: The Chemistry and Fertility of Sea Water. Cambridge: University Press. 27 HAYES, F. N.. ANDERSON, E. C., and ARNOLD, J. R., 1955: Liquid scintillation counting of natural radiocarbon. Proc. of the International Conference on Peaceful Uses of Atomic Energy, Geneva, r4. p. 188. HUTCHINSON, G. E., 1954: In The Emth as a Planet, G.
In The Earth as a Planet
  • G E Hutchinson
1899: Die Löslichkeit von Gasen in Flüssigkeiten
  • C Bohr
Der Borsäuregehalt des Meerwassers and seine Bedeutung bei der Berechnung des Kohlensäuresystems
  • Buch
Liquid scintillation counting of natural radiocarbon
  • F N Hayes
  • E C Anderson